Reversible, rotatable spray nozzle assemblies are widely used by spray devices, such as for high pressure, airless spraying of paint and other fluids. In a typical reversible spray nozzle assembly, a small spray nozzle, bore or tip is carried in a cylindrical, rotatable nozzle shaft. The nozzle shaft can be rotated 180 degrees, thereby reversing the direction of paint flow through the nozzle, bore or tip for cleaning nozzle obstructions. Typically the spray nozzles or tips are interchangeable with other spray nozzles carrying nozzles of various diameters and capacities.
Reversible spray nozzles or tips are generally utilized in hydraulic or airless spray painting or coating, wherein paint under high pressure is supplied to a spray gun and forced through a spray tip or nozzle, to aid in cleaning clogs that may form at the nozzle. Clogs can form due to the nature of the spray devices, wherein it is necessary for the spray opening in the spray nozzle be very small so that as the paint reaches the spray tip under high pressure and low velocity, it is accelerated through the spray opening at a high velocity and low pressure thereby forming a spray suitable for painting. Owing to the small size of the spray opening, the spray nozzle is susceptible to clogging. By providing a reversible tip, the spray nozzle can be turned generally 180 degrees and the paint or particles causing the clog can be discharged.
When using reversible spray nozzles or tips, user safety must be the most important concern. The spray that emanates from the nozzle of the spray device has the highest velocity and narrowest stream, and provides a risk of injury to the user. In view of this situation, prior spray devices have included various styles of spray guards to prevent the user's body from being hit by the spray jet near the spray nozzle orifice.
An additional problem spawning from the use of the reversible spray nozzle or tip is that it is possible to rotate the spray nozzle out of position, especially if the nozzle handle is bumped or jarred in the course of handling or moving the spray device. It is also possible for a user to fail to properly align and rotate the nozzle completely into the correct position before activating the spray devices. These circumstances can yield a condition, wherein the nozzle is not properly aligned when fluid flow is activated, that can result in accidents that can range in severity from nuisances such as erratic paint disbursement to injuries from skin or eye irritation, blindness, trip and falls, to possibly death.
U.S. Pat. No. 6,481,640 to Carey et al. relates to a saddle seal and washer insertion tool for airless paint spray tip assemblies having a housing containing a reversible tip holder of the type having cylindrical barrel with a handle formed of a polymer, located on and positioned generally transversely of the barrel, the housing having a longitudinal through bore for permitting delivery of paint, and a transverse bore for receiving the barrel of the tip holder, the insertion tool formed integrally with an end of the handle, the tool having a first portion with a width conforming to an internal diameter of the washer and a second portion extending beyond the first portion with a width conforming to a diameter of a bore in the saddle seal such that the washer can be received on the first portion and the saddle seal received on the second portion for alignment and installation into the housing.
U.S. Pat. No. 6,390,386 to Krohn et al. relates to a reversible airless spray tip. A positioning detent on the spray tip carrier handle snaps positively into place when a nozzle carrier is rotated into spray position, indicating that the tip is properly positioned for spraying. A piston seal has a slot-like fluid passage, which is preferably substantially rectangular in cross section. A rearward end of the piston seal is sealed by a resilient ring compressed directly against the face of an attached spray gun. A tip retainer is expanded by swaging after insertion, which forces a lip into a mating slot. The tip retainer also has an expanded chamber which diffuses reverse fluid flow for safety.
U.S. Pat. No. 5,749,528 to Carey et al. relates to a reversible spray tip or nozzle used with a spray gun or like device for hydraulically atomizing and spraying liquids such as paint. The spray tip includes a plastic housing having a forward extending spray tip guard integral therewith, a cylindrically shaped rotatable turret member diametrically received for rotation in the housing and having a diametric bore therethrough for receipt of a spray tip insert, and an elongated seal insert axially received in the housing upstream from the turret member. A securing nut rotatably mounted to the housing at the spray gun end thereof secures the reversible spray tip to the discharge end of the spray gun. The enhanced sealing effectiveness of the reversible spray tip permits effective sealing of the assembly by finger tightening of the securing nut.
U.S. Pat. No. 5,285,965 to McCutcheon et al. relates to a tip guard is provided to reportedly protect a user of an air-assisted airless paint spray gun from injury. The tip guard has a base having a shoulder and an aperture adapted for engagement to the air cap and tip of an air-assisted airless paint spray gun. The base further has a pair of transition portions extending axially forward from said aperture, where notches formed in the transition portions are adapted to engage the forwardly-extending horns of the air cap of an air-assisted airless paint spray gun. Each transition portion further has a pair of vanes extending forwardly and radially outwardly from the transition portion, where each of said pair of vanes is then joined by a crossbar.
U.S. Pat. No. 4,165,836 to Eull relates to an apparatus for attachment to a hand operated spray gun, comprising a cylindrical rotatable member having a spray orifice therein, which is rotatable between a spraying position and an orifice cleaning position, the rotatable cylindrical member having a metallic sealing member surface of matching shape and adjacent thereto, and a further resilient sealing member for permitting leakproof attachment to a spray device. The rotatable spray member is actuably coupled to a safety tip guard so as to become disassembled if the safety tip guard is removed.
U.S. Pat. No. 3,952,955 to Clements relates to an apparatus for fitting over the spray tip end of an airless paint spray gun, wherein the apparatus comprises a pair of forwardly projecting ears and a narrow slotted region opening said spray tip, and is adapted for key alignment with the spray tip.
Even through some prior art devices include features such as rotation stops or limits, such devices can be subject to user error and do not solve the problem of transverse misalignment in a direction perpendicular to the axial spray flow direction through the nozzle or tip.